The present invention relates generally to a fuel injection valve assembly and an assembling method therefor, and is applicable particularly, but not exclusively, to fuel injection into an internal combustion engine of a motor vehicle.
It is known in the fuel injection art that a fuel injection valve is arranged to have two injection holes in the case that the fuel injection valve is applied to fuel injection into a four-valve internal combustion engine with two intake valves per one cylinder. Such a fuel injection valve is illustrated, for example, in "JOURNAL OF NIPPONDENSO TECHNICAL DISCLOSURE" No. 33-065, published in 1984, wherein installed at the lower portion of the fuel injection valve is a cylindrical body having a through-hole at its center portion which is in turn coupled to a nozzle having two injection holes whereby the fuel exited from the through-hole is divided into two directions. Each of the two injection holes is directed to the corresponding one of two intake valves of the engine so as to prevent the injected fuel from striking the intermidiate portion between the two intake valves.
However, in such an arrangement to divide the fuel into a plurality of directions by means of a plurality of injection holes, the fuel injection valve is required to be finished with considerably high accuracy, particularly in terms of the diameter and axis of each of the injection holes. The irreguralities and variations thereamong causes variations in the amounts of fuel injected from the injection holes, resulting in poor responsibility and poor emission. The high manufacturing accuracy would be costly and troublesome. One attempt to relaxation of the high manufacturing accuracy involves providing a considerably great space between the cylindrical body and the nozzle. This has a great disadvantage, however, in that fuel remains in the space, resulting in the occurrance of a poor fuel/air mixture.